Chain-stitch sewing machine



Sept. was. 1,684,004

R. BECKER CHAIN STITCH SEWING MACHINE Filed Sept. 27, 1926 5 Sheets-Sheet 1 ept, n, 192s.

I RJBHECKER CHAIN STITCH SEWING MACHINE.

5 Sheets-Sheet Filed Sept. 27, 1926 M/messes R. BECKER CHAIN STITCH SEWING MACHINE Sept. 11, 1928.

Filed Se t. 27, 1926 5 Sheets-Sheet 3 Sept. 11, 1928. 1,684,004

' R. BECKER CHAIN STITCH SEWING MACHINE Filed Sept. 27. 1926 5 Sheets-Sheet 4 3 vmmw ior 5 Sheets-Sheet 5 R BECKER CHAIN STITCH SEWING MACHINE Sept, llil, 192%.

PATIENT, caries.)

RUDOLPH aeolian, or NORTH I'LAINFIELD, NEW JERSEY, ASSIGNOR'TO THE smena MANUFACTURING COMPANY, s ELIZABETH, NEW JERSEY, a conronarron on NEW 'anasny.

CHAIN-STITCH SEWING MACHINE.

Application filed September 27, 1926. serial renames.

This invention relates to sewing machines It has also been proposed to solve the proband has for an object to provide a simpli-' fied mechanism-for forming a chainstitch seam, which mechanism is capable of highspeed-operation. I

In chain-stitch sewing machines it is usual to provide ar'eciprocating needle for passing a needle-thread loop' through the workarid a looper for entering and detaining the needle-loop as the needle rises from the work and for presenting the needle-loop, or a loop of an under thread enchained with a needle-loop, for entry by the descending needle. in one known type of looper mechanism the looper is actuated by two cranks or eccentrics, one of which imparts to the looper loop-seizing and shedding movements and the other of. which gives the looper sidewise or so-called needle-avoiding movements, .whereby the looper passes along one side of the needle,-seizes a needle-loop and moves to the end of its stroke,is then given a sidewisemovement,.and is retracted along the other side-0f the needle-Path 7 It has. been proposed to simplify the machine b eliminating the sidewise movement of the 'lho'per, but it thenbecomes necessary to introduce a reciprocating spreader to as .sist in presenting the'threaddoop .to the'nee dle, since the needle cannot seize a loopfrom the looper whenthe latter retracts along the same side of the needle which it passes on its advancing stroke. I 7

Further, with machines of the above types, wherethe looper is actuated by one or more simple crank motions, it is necessary to in crease the amplitudes of motion ofithe needle and looper sufliciently to secure the proper relative timing of these implements at two points in the stitch-forming cycle, to, wit: a,..

when the 'looper seizes a needle-loop and b, when the needle enters the thread loo'p pre sentedby the looper.

It hasbeenproposed to reduce the .rnplitudes offlmotion of the needle and looper by modifying the actuating mechanism so asto give; the loop'eran irregular motion includingfdwells and periods ofrapid motion, but such irregular motion' only be secured by the use'of cams, toggle devices, etc. which complicate the actuat ng mechanism and are mechanically inferior to -simple crank-mo- -tions.

carries no thread andis crank operated and I properly timed to enter and detain the needleloop, and the other, a crank operated looper timed to present a loop to the descending needle. But little has been done toward developing machines involving. the last above proposed method, and such machines as have been developed are defective for several reasons among which may be mentioned-: 1". The

needle-loop is unduly expanded or drawn out and causes undue reeving of threadlthrough the needle-eye. 2. The loop-taker is depended uponfto drag the looper-thread loop through the needle-loop,which necessitates a harsh or sudden engagement of the looptaker with the looper-thread, tending to unduly strain the latter when'operating at high speed. 3. The loop-taker twists the loops andthus introduces a tendency-of such loops to kink or snarl while being drawn up.

. According to the present improvement there are provided separately timed crank driven loop-taking and loop-presenting implements. The loop-taker has a slender thread-engagingportion which moves in the direction of its length and seizes a needleloop without twistingor expanding or shifting such loop laterally. The loop-presenter or looper is preferably a simple two-motion blade which 'passesialoop of under thread throughthe needle-loop and istimed to present such loop to thedescending needle. The loop-taker may bein the form of a continuously rotating segmental ring which passes bodily through the needle-loop and moves such loop in the direction of feed or away from the needle-path. 1 Thus, the advantages of separately timed loop-taking and underthread carrying members are retained, while avoiding the disadvantages of known comducing the two-thread chain-stitch.

In the; accompanying drawings, Fig. 1 1s a side elevation, partlyin section, of a sew- ;ing machine embodying the invention. Fig.

2 is, a bottom plan view of the machine. Fig. '3 is a front end elevation of the ma-.

chine. Fig. 4 is a vertical section in the plane of the needle. taken transversely of the L tinas binations and arrangements of parts for pro- Ins 7 is a sectional View on the'line 7-7, Fig.-

1. 'Figs. 8, 9, 10 and 11 are a progressive series of elevations showing the cooperative action of the stitch-forming instrumentalities. Figs. 8, 9*, 10 and 11 are a series of views showing the corresponding positions of the needle-thread take-up device. Figs, 12, 13 and 14 illustrate a modified form of looper mechanism; Fig. 12 being an end View,

Fig. 13 arear side view and Fig. 14 a perspective view. Fig. 15 is a perspective view of the stitch 'as formed by the machine.

In-the embodiment of the invention illustrated in Figs.- Im 11 inclusive, the machine has a frame comprising a fiat bed 1 from which rises the standard 2 of the bracket-arm 3 terminating in the head 4 for the usual reciprocating needle and presser devices 5 and 6, respectively. The needle 5, which is carried by the needle-bar 7, is reciprocated by the usual link connection 8 with a'crank 9 on the main-shaft 10 journaled within the bracket-arm 3.

' 12, below the bed 1, is the lower rotary shaft Journaled in suitable bearing bushings 11,

13 which is geared at 14 to the vertical shaft 15; the latter being geared at 16 to the mainshaft 10. The bearing bushing 11 is fixed at one end in the downwardly extending bedlug 17 and at its other end is formed with a flat circular head 18 in the outer face of which is cut a raceway 19 for the segmental loop-taker ring 20 which, it will be noted in Fig. 4, is disposed wholly at one side'of the needle-path. A retaining ring 21 is applied to the outer face of the head 18 to hold the loop-taker 20 in the raceway 19. The looptaker ring is formed wit-h diametrically opposed shoulders 22, 23, which are engaged by the ends of the driving crank arms 24, 25, on the end of the shaft 13. The raceway 19 is slightly eccentric to the shaft 13 and, as a consequence, the ring 20 is driven by the arms 24, 25, alternately, so that a gap or space occurs between each driving arm and its respective shoulder on the ring 20 as such arm and shoulder pass the sewing point. These gaps permit the needle-loops to pass between the ring and its driving arms without hindrance. This form of loop-taker drive is well known and is shown, for example, in the patent to Fischer No. 793,127, of June 27, 1905. The Fischer machine is,

- however, designed to make only a single thread chain-stitch and the loop-taker moves contrary to the direction of feed whenseizing a needle-loop. In the present machine the loop-taker is so driven as to move in the direction of feed when seizing and detaining a needle-loop, so as to move the loop away from the needle-path. The center of the raceesa , eccentric 34 on the main-shaft .13,

way 19 should preferably be located slightly above and to the rear (or to the left, Fig. 3) of the center of the shaft 13.

Journaled on the bushing or sleeve 11, is the hub 26 of the looper-carrier 27 to which is secured by the screw 28, Fig. 5, the'lateral extension 29 at the rear end of the looperblade 30. The looper-blade 30 is formed at its forward end with a threadeye 31 and a thread-guide 32 is screwed to the rear end of the looper-blade. A collar 33 on the bushing 11 prevents the hub 26 of the loopercarrier from moving lengthwise of the bush:

The looper 30 is actuated by means of an The eccentric 34 is connected by the pitinan 35 to the arm 36 fixed to the rock-shaft 37 journaled in the frame lug 17. The rock-shaft 37 also has fixed thereto an arm 38 which is connected by a link 39 to the 1ooper-carrier 27. A simple crank motion is thus employed toactuate the the direction of feed in passing into the needleloop.

The machine isprovided with the usual four-motion feed-dog 41, Fig. 3, which is carried by the feed-bar 42 to which endwisefeeding movements are imparted by the food rocker 43 and rising and falling movements by the feed-lift 44. a

The needle-thread is preferably controlled by a rotary take-up comprising the usual spaced disks 45, 45, fixed on the main-shaft 10. A wire thread-guide 46 having a stripper slot 47 is disposed between the disks 45,

and spaced thread-guides 48 are disposed at the opposite or outer sides of such disks. An intermittent tension 49 is preferably provided for the needle-thread in'addition to the usual constant tension device 50. The intermittent tension is actuated by a cam 51 on the mainshaft 10 and applies anincreased tension to the thread as the take-up 45 is drawing up or tightening the stitch. No take-up is used for the under thread which runs from the supply to a fixed thread-guide 52 and thence through the thread guide 32 to the looper 30. I

The stitoh-formation is as follows. As the needle rises from its lowest point, Fig. 8, the

looper 30 is retracted and the loop-taker is timed-to seize the loop a of need advances and the incline-or rise 53 on the take-up 45 draws up or tightens the previous needle-loop b. The loop-taker 20, continues its excursion through the needle-loop. wwithe-thread. As the needle continues to rise the 10oper30 which is presented by the looper 30. As the looper 30 retracts, it leaves its loop 0 around the needle and as the loop-taker 20 completes its excursion the needle-loop aescapes from the loop-taker, Fig. 11, and is partially drawn up as the loop Z), Fig. 8, by the cam rise 54 on the take-up 45. 'The depression immediately preceding the .cam rise 5-1 effects a momentary slackening .of the needle-thread as the loo-p a escapes from the heel of the loop-taker and thus avoids a harsh snapping. of such loop over the loop-taker heel.

In the modified form of the invention illustrated in Figs. 12, 13 and 14, the threaded looper 53 does not oscillate about an aXis concentric with the loop taker driving shaft 13 but is mounted on a shaft 54: disposed below and parallel to the shaft 13. The shaftz54 has fixed thereto an upwardly inclined pin 55 which enters a socket in the follower block 56 embracing'the crank or eccentric 57 on the shaft 13. The timing of the looper 53 relative' to the needle 5 and loop-taker 20 is substantially the same as that of the looper 31' first described. The modified form of looper drive is structurally somewhat simpler than the first described looper drive, as the arm 38 ,aiid'lirlk 39 are eliminated.

I It; will be observed that .the operating mechanisms :for the looper and loop-taker members are extremely simple; comprising merely a rotary shaft and one simple crankmotion. The needle-bar stroke can be reduced'to a minimum, as the loop-taker and looper can be independently timed relative to the needle, regardless (if the length of the needle-stroke. The mounting of the looptaker and looper to move about parallel or coincident axes also makes for simplicity and favorable cooperation of the parts.

- The inventionis not to be understood as limited to the form and arrangement of parts showli fand described'as it is obvious that the mechanism shown is susceptible of considerablemodification within. the spirit and scope of the invention.

Having thusset forth the nature of the invention, whatI claim herein is:

1. In a sewing machine, in combination, feedin mechanism, a reciprocating needle, a loop-ta er adapted to seize and detain ,a

.needle-loopand to cooperate with the feeding mechanism to move the detained needle- -loop out. of the needle-path, and means separate from said loop-taker forpas sing a loop I of under thread through the detained needleloop for entry by the descending needle.

2. In a sewing machine, in combination, feeding mechanism, a reciprocating needle, a loop-taker in the form of a segmental ring rotating in the direction of feed and adapted to seize and detain a needle-loop and to cooperate with the feed to move the detained needle-loop out of the needle-path, an under thread looper, and means for. moving said looper into the seized needle-loop contrary to the direction of feed to carry a loop of under thread through the needle-loop for entry by the descending needle.

'3. In a sewing machine, in combination, a reciprocating needle, a loop-taker comprising a segmental ring, and a loop-presenter, said loop-taker and loop-presenter being separately timed and movable about axes extending in the same direction.

4. In a sewing machine, in comb nation, a

reciprocating needle, a rotary looptaker in the form of a segmental ring, a loop-taker raceway, a loop-taker driving shaft, a looptakcr driver carried by said shaft, :1. twomotion oscillatory looper, and a crank on said shaft and connections for oscillating said looper.

5. In a sewing'machine, in combination, a reciprocating needle, a rotary loop-taker in the form of a segmental ring, a loop-taker raceway, a loop-taker driving shaft, a looptaker driver carried by said shaft, and a reciprocating looper having a blade operating in a plane substantially coincident with the plane of said loop-taker.

6. In a sewing machine, in combination, a reciprocating needle, a loop-taker comprising a segmental ring, a loop-taker supporting raceway, a loop-taker driving shaft, a looper, a looper-supporting shaft mounted below and substantially parallel with the loop-taker driving shaft, and a crank on said loop-taker driving shaft; and connections for oscillating: said looper-supporting shaft.

7. In a sewing machine, in combination, a

reciprocating-needle, a-loop-taker having a slender loop-engaging portion adapted to enter and detain a needle-loop until the needle has risen from-the work, without expanding or laterally shifting such loop, a reciprocating looper, and means for moving said-looper into the detained needle-loop, said looper operating to present a thread-loop for entry by the descending needle.

' 8: In a sewingmachine, in combination, a reciprocating needle, a loop-taker having a slender loop-engaging portion .in the form of a segmental ring adapted to enter and detain a needle-loop until-the needle has risen from the work, without expanding or laterally shifting such loop, .a' reciprocating qlooper, and-means for moving said looper into the de' tained needle-loomfsaid loopen'operating to scending needle.

present a threadgloop for entry" loy the d 9. In a sewing machine, in combination, a reciprocating needle, a loop-taker having a slender loop-engaging portion in form of a segmental ring, means forcontinuously rotating said ring, a reciprocating looper, and

means for moving said looper into a needle I loop detained by saidring, said loop'er operatloop a reciprocating looper, and means for moving said .looper,into thedetained needleloop, said looper operating' to present a thread-loop for entry by the descending needle. g Y g 11. llnfa sewing machine, in combination, a reciprocating needle, a loop-taker having a agesaooe has risen from the Work, Without expanding slender loopeengaging portion adapted to en-- ter and detain a needle-loop untilthe needle or laterally shifting such loop, and a looper in the form of a reciprocating eye-pointed blade with, means for projecting it into the detained needle-loop Without increasing the size of such needle-loop, said looper operating topass a loop of under thread through the "needle-loop and present such under thread .loop for entry by the descending needle.

12. In a sewing machine, in combination, feed mechanism, a reciprocating needle, a -loop-taker having a pointed slender-bodied thread-engaging portion mnvino' in thedirection of feed to seize a needle-loop, a loop presenter, and means for moving said loop-presenter into the needle-loop contrary to the direction of feed, said loop presenter operating to present a thread-loop for entry by the descending needle. In testimony whereof, I have signed my name to this specification. l

RUDOLPH nnonnn. 

